PROJECT SUMMARY Pain management is a significant unmet medical need. Palmitoylethanolamide (PEA) is an endogenous analgesic substance that plays crucial roles in the peripheral control of pain and inflammation. Its biological actions are terminated by the cysteine hydrolase, N-acylethanolamine acid amidase (NAAA). During the Phase 1 of the present SBIR-2 application, we have developed the first class of potent, selective and orally available NAAA inhibitors. The lead compound in this class, a benzothiazole piperazine derivative called ARN19702, exerts profound analgesic effects in animal models of acute and chronic pain, suggesting that NAAA inhibition may offer a transformative approach to pain therapy. Work done during the Phase 1 of the present application has demonstrated that ARN19702 (i) is a potent and reversible inhibitor of mouse and human NAAA; (ii) displays a high degree of target selectivity when assayed on a panel of 96 receptors, ion channels, enzymes and membrane transporters, or toward other cysteine hydrolases; (iii) is systemically active and, unlike previous NAAA inhibitors, has excellent oral bioavailability; and (iv) suppresses pain with high efficacy and prolonged duration of action in four distinct animal models. Based on these properties, we selected ARN19702 as candidate for preclinical development. The objective of present proposal is to complete all key activities needed to enable the filing of an Investigational New Drug (IND) for ARN19702 in postoperative pain, a market that is now served by addictive opioid drugs or opioid/NSAID combinations. Our specific aims are: Aim 1. Determine the metabolism and pharmacokinetics properties of ARN19702. We will collect the DM-PK data necessary to support the IND filing of ARN19702. Aim 2. Determine the nonclinical toxicology properties of ARN19702. We will collect the toxicology data necessary to support the IND filing of ARN19702. Aim 3. Determine the nonclinical pharmacodynamics of ARN19702. To facilitate the clinical development of ARN19702, we will develop a circulating biomarker for NAAA inhibition and enhancement of PEA-mediated signaling. The studies will be directed by an experienced team of scientists and pharmaceutical professionals, which include NeoKera?s cofounders, Dr. Edward Monaghan (PI) and Professor Daniele Piomelli (co-PI), along with independent consultants Dr. William Schmidt, a clinical pharmacology consultant specialized in pain therapy; Dr. Fred Reno, a consultant in toxicology; Dr. George Mooney, a consultant in Chemistry, Manufacturing and Controls; Dr. Edward (Ned) Whittamore, a consultant in regulatory affairs; Nancy Levine, consultant for pharmacokinetics; and Dr. Joe Rinehart (Vice Chair for Research at UCI?s Department of Anesthesiology) as pro bono clinical consultant. The proposed studies will provide the necessary data in support of an IND filing for ARN19702 as a treatment for general acute pain.